Wrench for shielded spark plugs



March 18, 1947. J, P, JONES WRENCH FOR SHIELDED SPARK PLUGS Filed Sept.25, 1944' INVENTOR. Q John Paul Jnes.

flrroRNEy.

Patented Mar. 18,1947

UNIT ED STAT E S O F F lC E 2,417,598 WRENCH FOR SHIELDED SPARK PLUGSJohn PaulJ ones, Brownsville, Tex; Applicationseptember 23, 1944; SerialNo. 555,561.

This invention relates to socket wrenches for shielded sparkplugs of thetype used in airplane engines and, among. other objects, aims to providea greatly improvedsocket member adapted to be positively engagedwith.and gripped on a non-circular head or nut of a shielded spark plug. bymeans of a screw threaded nut engaging the shield member. or shell toprevent damage to thelplug when. it is tightened or removed.

Another aim is to provide a simplified form of cylindrical socket.member and wrench handies adaptedto engage the. holding nut and thesocket member. The main idea is to provide an improvedsocket wrench ofthistypewhich great- 1y facilitates the insertionand removal of shieldedspark plugs used in larg airplane engines.

Other aims and advantages of the invention will appear in thespecificationwhen considered in connectionwith the accompanyingdrawings, wherein:

Fig. 1 is asectional view,partly in elevation, showing one form of the,wrench applied to a shieldedspark plug;

Fig. 2 is a vertical sectional'view taken on the line 2-2 of Eigfilg,showing, parts oithe socket member;

Fig. 3is a sectional view taken on the line 3-3 ofFig. 11.

Fig. 4 is an upper end view ofthe socket shown in Fig. 2;

Fig. 5 is a sectional view taken on the line 5-5 of F g; 2;

Fig. 6 isalongitudinal view, partly in section, of a handle formanipulating the socket member; and

Fig. 7 is a fragmentary view, similar to Fig. 4', showing the handleapplied to the upper end of a socket member.

Referring more particularly to the drawing, the special type of socketwrench there shown, is designed to be used on a shielded spark plug l0,wherein an insulating shield is protected by a shield member or tubularshell H having screw threads l2 at its upper end to which a conductorfitting or elbow (not shown) is adapted to be engaged. Champion sparkplugs are commonly used in airplane engines. They have a narrow nutsection l3 which has to be engaged by a socket wrench to remove andreplace them. Experience has demonstrated that ordinary socket wrenchessoon damage the hexagon or non-circular heads to such an extent that thespark plugs have to be discarded. This is especially true when the plugsbecome frozen in an engine and require considerable turning effort to 5Claims. (01. 81-125) remove them. In accordance withthls invention, thescrew threads in the shield member orshell ar utilized, for the purposeof positively grip- ,ping and holdinga socket member on theplug,

thereby preventing accidental disengagement from. the plugand consequentdamage to the non-circular head.

Referring to Figs. 1 and 2; the socket wrench portion, is shown ascomprising an elongated tube l4 having a non-circular socket IE3 at itslower end and. presenting an internal sleeve it tel'escoped within thetube. The lower socket member is preferably, although not necessarily,formed" of a separate piece; and welded in the lower endof the tube; sothatit presentsa should'er 'llontheinside of the tube at a heightsubstantially equal to the height of the plain shank ll of theprotecting sleeve member or shell H2 Thetube is shown. as having anelongatedsight opening, IS on one. side and a tubular, floating nut I!)is. slipped into the tube so that it can rotate with respect? to thetube. It is shown as having, a screw threaded, internal thimble 20adapted to be screwed on the screw threaded portion l2'of theshell orsleeve member Ii. Its lower end engages the shoulder. H to clamp thesocket l5 on the nutportion l3 of the plug, with the lower end of thesocket engaging the usual flange '2 l of the plugbelow the nut portion.

The floating nut is shown as having a squared socket portion 22 at itsupper end adapted to be engaged by the shank of a small wrench handle23; inserted in.the.upper end of the tube: l4, as shown in Fig. 1'. Whenthe floating nut is screwed home on the screw threads l2 oi the sleeveportion l l, the spark plug is positively engaged by the socket and thewrench handle 23 is then removed.

The upper end of the sleeve 14 has a square socket member 24 adapted tobe engaged by an ordinary socket wrench handle. In this instance, thereis shown a handle 25 having a square shank 26 at its upper end and apivoted shank 21 at its lower end adapted to be turned at a right angle,as shown'in Fig. 7, to engage the socket 24 and afford ample leverage toturn the wrench socket. Of course, other male and/or female handles canbe employed to extend the effective length of the socket wrench in casethe spark plugs are relatively inaccessible. For example, a second plugsocket member M can be employed to engage the pivoted shank 21, whenturned at a right angle, while the straight shank 26 is engaged in theupper socket 24. Moreover, the pivoted shank 21, when in the positionshown in Fig. 6,

can be engaged in the socket 24 and an ordinary straight handle (notshown) inserted in an opening 28 near the upper end of the handle. Thehandle 25 is shown as being knurled to facilitate gripping. Likewise,the barrel or outer surface of the tube l4 may be knurled to facilitateturning by hand when the spark plug is loose in its screw threadedopening.

From the foregoing description. it will be seen that the wrench isdesigned to protect spark plugs and prevent damage to the non-circularheads. Also, it prevents accidental disengagement of the spark plugsfrom the sockets when the spark plugs are removed. Experience hasdemonstrated that a wrench of this type is greatly in demand. It hasserved the purpose of removing spark plugs many times without anynoticeable damage. In fact, it is contemplated that it will displaceother socket wrenches for removing and replacing shielded spark plugs.

Obviously, the invention is not restricted to the particular embodimentherein shown and described.

Having thus described the invention what is claimed is:

1. A spark plug wrench of the character described comprising incombination, a tubular member having a plug engaging socket at its lowerend; a floating nut rotatably mounted within the tube adapted to engagea screw threaded shield member on the upper end of the spark plug; astop shoulder for the nut in the tube, so arranged that the nut willclamp the socket on the spark plug; a removable wrench handle for thefloating nut adapted to be inserted in the tube; a wrench socket in theupper end of the tube; and a handle having a shank adapted to engagesaid upper socket.

2. A socket wrench for spark plugs having a screw threaded shield membercomprising an elongated tube having a wrench socket to engage the sparkplug; a shoulder within the tube around the shank of the shield member;a nut confined to rotate and slide up and down in the tube and adaptedto be screwed on the shield member into engagement with said shoulder toclamp the wrench socket on the spark plug; a wrench handle removablyengageable with the floating nut adapted to be inserted in and removedfrom the tube; and a non-circular wrench socket in the upper end of thetube adapted to be engaged by the shank of a wrench handle.

3. A spark plug wrench of the character described comprising incombination, a tubular 4. member having a plug engaging socket at itslower end; a shoulder portion above the spark plug engaging socketwithin the tube; a floating nut rotatably mounted within the tubeadapted to be screwed on a screw threaded shield member on the upper endof the spark plug and into engagement with said shoulder to clamp thesocket on the spark plug; a removable wrench handle for the floating nutadapted to be inserted in the tube; a wrench socket in the upper end ofthe tube; and a handle having a shank adapted to engage said uppersocket.

4. A socket wrench for spark plugs having a screw threaded shieldmember, comprising in combination, an elongated tube having a wrenchsocket to engage and rest on the head of a spark plug; a shoulder withinthe tube around the shank of the shield member; a nut confined to rotateand slide up and down in the tube and adapted to be screwed on theshield member into engagement with the shoulder to clamp the wrenchsocket on the spark plug; a wrench handle removably engageable with thefloating nut adapted to be inserted in and removed from the tube; and anon-circular wrench socket within the upper end of the tube andconfining the floating nut therein.

5. A wrench for spark plugs having a screw threaded shield member,comprising a tubular section having a plug socket in one end to rest onthe head of a spark plug; an annular shoulder above the plug socket; afloating nut confined in the tubular section adapted to be screwed onthe shield member into engagement with said shoulder to clamp the plugin the socket; a nut operating member insertable through the other endof the tubular member and removably engageable with said nut; and handlereceiving means in said other end of the tubular member. JOHN PAULJONES.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,235,572 Culbertson Mar. 18,1941 2,358,249 Portuondo Sept. 12, 1944 FOREIGN PATENTS Number CountryDate 418,760 British Oct. 31, 1934 233,875 British May 21, 1925

